Unless the surface is damaged or has been repaired the factory treated steel should not rust. I've used countless gallons of Waxoyl on classics over the years but would hesitate about recommending it on a Zed. Don't get me wrong, it's good stuff but can trap surface dirt and moisture and is flammable around high temperature components (engine bay, exhaust, brakes etc). It also smells when warm.
IMO unless you are protecting known damaged/repaired areas it's probably better to keep things cleaned regularly and check exposed surfaces for damage.